The mouse is an important model organism for probing the relationships between genetics and human disease. The ability to introduce genetic modifications has strengthened the value of the mouse as a model organism, but resulted in the creation of thousands of new mouse strains. These strains can be a burden to maintain but represent an invaluable asset to the scientific community. Centralized resources such as those at The Jackson Laboratory (TJL) play an important role in managing these strains by acquiring, maintaining and distributing them to the community. Thus, the Cryopreservation Resource plays a critical role in there source program at The Jackson Laboratory. Acting as a central resource for the cryopreservation of strains and distributing them as frozen germplasm or as mice recovered from frozen germplasm, the Cryopreservation Resource facilitates the cost-effective archiving, maintenance and distribution of low-demand strains. Without the TJL Cryopreservation Resource, more than $5.7 million per year would be required to maintain this collection. The value of this resource to the community is also important and can be evaluated in part on its scale and in part on its use. The resource holds one third of all of the cryopreserved strains available globally, recovering and shipping nearly 7.000 mice to fill 600 orders from around the globe. Support from this grant and other funding sources has funded innovation reducing the time and cost of cryopreserving strains by 50% and reduced the average time to fill requests by 20%- two factors that will be critical as growth continues to accelerate. Over time, the Cryopreservation Resource has become increasingly self-sufficient, no longer relying on this grant to support the cryopreservation of strains and recovering fees to support distribution of strains, but still relying on this grant for critical infrastructure and research support. The purpose of this proposal is to assure the continuity of the repository by supporting the infrastructure required to ensure that scientifically valuable research models will always be available and to help develop more cost effective methodologies for the preservation and recovery of these irreplaceable resources. Relevance to Public Health: Inbred mice are accepted as the primary model organism for analyzing and understanding inherited human disorders. The Jackson Laboratory Cryopreservation Resource is the sole source for nearly 2,000 different mouse strains and serves as the primary backup for 1,000 more, 40% of all strains listed in the International Mouse Strain Resource. Failure to have access to the strains held by the Cryopreservation Resource would delay more than 600 research projects each year by months or years, directly impacting the development of new therapies to treat human disease.